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9 result(s) for "Quijano-Avilés, Maria"
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Changes in GC-MS metabolite profile, antioxidant capacity and anthocyanins content during fermentation of fine-flavor cacao beans from Ecuador
The fermentation of fine-flavor cacao beans is a key process contributing to the enhancement of organoleptic attributes and monetary benefits for cacao farmers. This work aimed to describe the dynamics of the gas chromatography-mass spectrometry (GC-MS) metabolite profile as well as the antioxidant capacity and anthocyanin contents during fermentation of fine-flavor cacao beans. Samples of Nacional x Trinitario cacao beans were obtained after 0, 24, 48, 72, 96, and 120 hours of spontaneous fermentation. Total phenolic content (TPC), ferric reducing antioxidant power (FRAP), and total anthocyanin content were measured by ultraviolet-visible (UV-Vis) spectrophotometry. Volatiles were adsorbed by headspace solid phase microextraction (HS-SPME) while other metabolites were assessed by an extraction-derivatization method followed by gas chromatography-mass spectrometry (GC-MS) detection and identification. Thirty-two aroma-active compounds were identified in the samples, including 17 fruity, and 9 floral-like volatiles as well as metabolites with caramel, chocolate, ethereal, nutty, sweet, and woody notes. Principal components analysis and Heatmap-cluster analysis of volatile metabolites grouped samples according to the fermentation time. Additionally, the total anthocyanin content declined during fermentation, and FRAP-TPC values showed a partial correlation. These results highlight the importance of fermentation for the improvement of the fine-flavor characteristics of cacao beans.
Effect of Cocoa Bean Shell Addition on Metabolite Profile and Antioxidant Activity of Herbal Infusions
Cocoa bean shell (CBS) is a by-product with aromatic characteristics that can enhance the aroma and bioactivity of herbal infusions. This study was aimed to determine the effect of the addition of cocoa bean shell on the metabolite profile and antioxidant activity of infusions made with Ilex guayusa and Vernonanthura patens and their mixtures. Metabolite profile was analyzed by gas chromatography–mass spectrometry combined with multivariate analysis. Total polyphenol content and flavonoids were determined by the Folin-Ciocalteu method and by the flavonoid-AlCl3 complex, respectively. Antioxidant activities were measured by the decolorization assay of the 2,2-diphenyl-1-picrylhydrazyl radical and the ferric reducing antioxidant power. The results revealed that the addition of CBS increases the content of phenolic acids in the infusions (caffeic acid, 4-hydroxybenzoic acid, and pyrocatechol). Nonetheless, the antioxidant activity of the infusions decreased with the addition of CBS (16.21 to 2.74 TEAC). Carboxylic acids and derivatives, major compounds present in the infusions prepared with V. patens, were the metabolites that showed the highest correlation with the antioxidant activity. This study suggests that the infusions made with CBS present a profile of metabolites different from the infusions of I. guayusa, V. patens, and their mixtures.
Physicochemical characterization of Theobroma cacao L. sweatings in Ecuadorian coast
In 2014, Ecuador generated 141,000 MT of cocoa sweatings equivalent to 12,320 MT of reducing sugars that through fermentation can become Bioetanol. Cocoa sweatings was characterized to determinate its potential as biofuel. Methodologies described by AOAC 2005 standards were used. Values of 10.6 Brix; pH 3.58; density 1.10 g/ml, total sugars 12,33% reducing sugars 6.39% were observed. Chemical groups such as alkaloids, reducing sugars, and coumarins triterpenoid were identified by phytochemical screeninng. 20 chemical compounds were detected using by gas chromatography mass spectrometry (GC-MS): 3 carboxilic acids, 4 sugar acids, 3 sugar alcohols, 2 amino acids, 1 furan, 2 lactones, 1 monosaccharides, 2 disaccharides and 2 glycosides. They represent the 11.08% of total compounds separated, and Sucrose (2.15%), glucose (2.13%) and fructose (4.42%) were identified by high performance liquid chromatography (HPLC). The study showed that for each kilogram of dry cocoa produced 0.59 kg of mucilage are obtained and its sugars are an interesting source of raw material for the production of second generation bioethanol, results that contribute to reducing the environmental impact that generate these waste.
Effect of drying methods on physical and chemical properties of Ilex guayusa leaves
The influence of air-drying (AD), convection oven (CO) and solar drying (SOD) on the physical and chemical properties of Ilex guayusa leaves is discussed. Total ash (%), acid-insoluble ash (%), watersoluble ash (%), residual moisture (%) and caffeine content (%) were estimated. Additionally, alkaloids, flavonoids, reducing sugars, saponins, steroids, quinones, fats, phenols and tannins detection of dry leaves extracts were assessed. The results revealed that parameters of physical analysis were not affected by the drying techniques. The highest amount of secondary metabolites in ethanol and aqueous extracts were detected. In general, convection oven dried leaves showed the highest caffeine content (3.71%) and the lowest drying time (13 h) compared to other drying methods. The results revealed a fast method to dry Ilex guayusa leaves and indicate that this species possess a variety of bioactive compounds beneficial for health. Our results revealed an effective quick method to dry Ilex guayusa leaves without altering the content of beneficial bioactive components.
Field evaluation of plants molluscicide against Pomacea canaliculata
Two plants reported as molluscicides have been tested against the snail Pomacea canaliculata under field conditions. The molluscicide activity of the formulation Sapindus saponaria L. (100%) was compared with the mixture of Sapindus saponaria L. and Solanum mammosum L. (50:50, w/w) using different concentrations (10, 50, 100, 200, 400 mg.L^sup -1^). LC^sub 50^ and LC^sub 90^ values were calculated using Probit Model. Sapindus saponaria L. (100%) showed higher molluscicide activity and reported a LC^sub 50^ value of 66.6 mg.L^sup -1^. These results have not been informed in the literature.
Polyphenols extracted from Theobroma cacao waste and its utility as antioxidant
Cocoa production is economically significant in Ecuador but large quantities of waste are generated during the industrialization process. The aim of this study is to improve the quality parameters of cooking oils using polyphenols extracted from cocoa bean shell. A 32 factorial design was used in the determination of optimal conditions for the use of polyphenols as antioxidant for the oils. The polyphenol concentration added to the oil (0%, 0.02%, and 0.04%) and the times of repeated use (0, 10 and 20 times) were consider as factors and free fatty acids, peroxide index, clarity, and DPPH antioxidant activity were selected as the dependent variables. Response surface method was applied for optimization. The required concentration for stabilized cooking oil was 0.01 % with a desirability value of 97.59%. These results are novel and prove the usefulness of cocoa waste as a source of antioxidants.
Linear programming formulation of a dairy drink made of cocoa, coffee and orange by-products
The agricultural industry generates large amounts of residues, commonly considered as waste. By-products from industrial processing of cacao, coffee and orange were used to formulate a dairy drink. The enriched dairy product was elaborated using a 10% aqueous extract of cocoa bean shells, coffee silverskin and orange peel. A design of mixtures of extreme vertices was applied to test the proportions of the ingredients of the aqueous extract. Sensorial characteristics like taste, odor, color and appearance were evaluated by a semi-trained testing panel applying the method of multiple comparisons, comparing the test formulations with a commercial drink of coffee and cocoa. The test formulations that were rated similar to the reference drink were selected to improve their total polyphenol content (TPC) applying a mathematical process of linear optimization. This approach indicated an optimal formulation containing 74 % cocoa bean shells, 24.50% coffee silverskin and 1.50% orange peel. This formulation gave TPC values of 5.74 ± 0.41 Gallic Acid Equivalent (GAE) mg/g, 82.20 ± 0.08% antioxidant activity by the diphenylpicrylhydrazyl (DPPH) assay and 114.78 mg/l caffeine content. The results demonstrate the feasibility to produce a drink enriched in antioxidant compounds retaining good sensorial attributes using industrial by products.
Antioxidant activity and GC-MS profile of Conyza bonariensis L. leaves extract and fractions
The 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing power (FRAP), and semivolatile compounds of Conyza bonariensis L. leave extract and fractions are discussed. A methanolic crude extract was obtained through maceration, and subsequently, n-hexane, chloroform, and ethyl acetate fractions were collected using a solvent-solvent partition. Total phenols, flavonoids, and antioxidant activity assays were performed in an ultraviolet-visible (UV-Vis) spectrophotometer, and the results were expressed as Gallic Acid, Quercetin, and Trolox equivalents respectively. The findings achieved indicate that ethyl acetate fraction showed the highest DPPH radical scavenging capacity (90.69±3.16%) at 500 µg mL-1, and reduced the ferric tripyridyltriazine complex (Fe3+-TPTZ) with values between 19.68 and 2,355.37 mg Trolox equivalent (TE) g-1. It was identified 28 phytoconstituents through Gas chromatography-mass spectrometry (GC-MS). The scavenging activity of ethyl acetate fraction could be correlated mostly to the presence of eugenol, trans-isoeugenol, lucenin-2, methyl salicylate, and syringic acid. This study reveals that the ethyl acetate fraction could be used as a good source of antioxidants for health benefits.
Effect of drying methods on physical and chemical properties of Ilex guayusa leaves
En este trabajo se discute la influencia del secado al aire (AD), el horno de convección (CO) y el secado solar (SOD) sobre las propiedades físicas y químicas de las hojas de Ilex guayusa. Seestimaron las cenizas totales (%), las cenizas insolubles en ácido (%), las cenizas solubles en agua (%), la humedad residual (%) y el contenido de cafeína (%). Además, se analizó la presencia los alcaloides, flavonoides, azúcares reductores, saponinas, esteroides, quinonas, grasas, fenoles y taninos en extractos de hojas secas. Los resultados revelaron que los parámetros del análisis físico no se vieron afectados por las técnicas de secado. La mayor cantidad de metabolitos secundarios se detectó en el extracto etanólico y acuoso. En general, las hojas secadas al horno de convección mostraron el mayor contenido de cafeína (3,71%) y el menor tiempo de secado (13 h) en comparación con los otros métodos de secado empleados. Los resultados obtenidos revelaron un método rápido para secar hojas de Ilex guayusa sin alterar el contenido de componentes bioactivos beneficiosos para la salud, estudios que no han sido reportados.