Search

La papaya es un fruto climatérico que tiene una vida en anaquel corta. Una opción para prolongar la vida útil de este fruto es el uso de recubrimientos. El objetivo del presente estudio fue evaluar el efecto del recubrimiento a base de alginato extraído de Sargassum fluitans adicionado con nanopartículas de plata (NpAg) sobre la vida en anaquel de papaya (Carica papaya L. var. Maradol). Las NpAg se obtuvieron mediante síntesis verde. Las papayas, en grado de madurez 3, fueron recubiertas con tres soluciones: solución 1 (2.49 % alginato), solución 2 (2.49 % alginato y 1.1 mg NpAg/mL) y el grupo control (agua). Los frutos se pincelearon y se almacenaron 15 días a 25 °C y 75 % de humedad relativa. Los frutos recubiertos con las soluciones 1 y 2 mantuvieron valores óptimos de firmeza (6.9 y 6.6 MPa), sólidos solubles totales (11.1 y 11.06 °Brix) y contenido de ácido ascórbico (22.31 y 23.02 mg AA/g pulpa) durante 6 días más que el control. Los recubrimientos de alginato de sodio extraído de S. fluitans adicionado o no con NpAg retardaron la maduración de la papaya. Esta tecnología permite prolongar la vida en anaquel de la papaya a 25 °C sin utilizar refrigeración.

The high susceptibility to deterioration and diseases during the supply chain and/or during the storage of fresh products is a problem in the industry, and edible films are proposed as efficient methods to preserve its quality. The objective was to obtain and characterize silver nanoparticles (AgNPs) and determine their effect on optical, barrier and mechanical properties of alginate-based films. The alginate was extracted from Sargassum fluitans. AgNPs were obtained by green synthesis using Gliricidia sepium. The UV–Vis and dynamic light scattering (DLS) were used to characterize the AgNPs. The antifungal activity of AgNPs was investigated using several fungal strains. Films were formulated by using 2 and 3% alginate, as well as 0, 1, and 2 mg of AgNPs per mL of formulation, with glycerol as a plasticizer. A randomized experimental design was used to test the effect to alginate and the AgNPs concentrations. The results were analyzed by an ANOVA test (p

Tofu is one of the main foods made with soybeans. The aim of this work was to evaluate the effect of L. plantarum and L. fermentum on the volatile compounds and sensorial profile of fermented tofu during ripening. The soy milk was fermented separately with two native strains (L. plantarum or L. fermentum) until reaching a pH of 5.5, and the fermented tofu was obtained. The tofu obtained by acidification with lactic acid was used as a control and was characterized by microbial survival (L. plantarum, L. fermentum, and P. freudenreichii) for 0, 20, and 40 days of storage at 15 °C. Moreover, the lactic and acetic acid content was determined by high-performance liquid chromatography (HPLC), and the volatile compounds were evaluated by gas. Chromatography-mass spectrometry (GC-MS). The results were analyzed by an ANOVA test (P 0.05). After storage, the lactic acid bacteria (LAB) survived in the fermented tofu at a concentration higher than 8.0 log CFU/g after 40 days of storage. The shelf life of fermented tofu obtained by acidification was fewer than 20 days because of the presence of fungi and yeasts. The hexanal content was reduced by approximately 96% (P 0.05) in the tofu obtained by fermentation compared with the control. This process for fermented tofu production employing two native strains could be used for industrial purposes.

The use of phytonanoparticles in agriculture could decrease the use of fertilizers and therefore decrease soil contamination, due to their size being better assimilated in plants. It is important to mention that the nanofertilizer is slow-releasing and improves plant physiological properties and various nutritional parameters. The influence of soil and foliar applications of phytonanoparticles of ZnO with the Moringa oleifera extract under three concentrations (25, 50, and 100 ppm) was evaluated on the cherry tomato crop (Solanum lycopersicum L.). Synthesis of the phytonanoparticles was analyzed with ultraviolet-visible spectroscopy (UV-Vis) and infrared transmission spectroscopy with Fourier transform (FT-IR), as well as the analysis with the dynamic light scattering (DLS) technique. The morphometric parameters were evaluated before and after the application of the nanoparticles. The minerals’ content of fruits was done 95 days after planting. Results showed that soil application was better at a concentration of 25 ppm of phytonanoparticles since it allowed the greatest number of flowers and fruits on the plant; however, it was demonstrated that when performing a foliar application, the fruit showed the highest concentrations for the elements Mg, Ca, and Na at concentrations of 511, 4589, and 223 mg kg−1, respectively.

Different types of nanoparticles (NPs) are increasingly used in multiple sectors such as industry, medicine and agriculture. This application has increased the possibility of NPs accumulating and c...

Plant growth regulators naphthaleneacetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), 6-Benzylamino purine (BAP) were evaluated at different concentrations (0, 0.5, 1.0, and 2.0 mgL-l) in three different explants (leaf, stem, and root) on the induction of responses morphogenic. In the suspension cell culture establishment, callus obtained from the stem were used and two concentrations of coconut water (20 and 40% v/v) were evaluated to increase the disintegration of the cell suspension. Bonediol was quantified using the HPLC technique in callus obtained from different explants (leaf, stem, and root) and suspension cell cultures. Higher callus formation was obtained in stem explants, with BAP at 1.0 mgL-l indirect organogenesis was obtained and with 2,4-D at 0.5 and 1.0 mgL-l somatic embryogenesis. Bonediol concentration detected was 49.57 mg/g callus, derived from stem explant. During the cultivation of cells in suspension, greater disintegration of the compact calli was observed with 20% coconut water. Bonediol concentration in suspension cell cultures was 24.44 mg/g dry cell. The objective of this work was to evaluate the effect of growth regulators on callus formation as well as the quantification and determination of bonediol content in callus and suspension cells of Bonellia macrocarpa.

Agronomic biofortification is a process used to increase the concentration of essential elements in plants through fertilization and thus improve their nutritional quality. Increasing the content of Zn+2 in Stevia rebaudiana plants would imply adding value to the crop. The use of ZnO phytonanoparticles, in addition to increasing the content of Zn+2, can also generate an inductor effect that promotes the synthesis of metabolites of commercial interest. This study reports the effect of fertilization with ZnO phytonanoparticles on morphometric parameters of S. rebaudiana plants and the content of Zn+2, stevioside, rebaudioside A, total phenols, flavonoids and the antiradical activity of leaf extracts. Biofortification was carried out in a hydroponic culture using peat moss/agrolite as a support under a completely random experimental design. The green ZnO nanoparticles were added via root at different concentrations. The physiological and morphometric parameters of the plant were not affected with respect to the control by the use of phytonanoparticles. The biofortification of S. rebaudiana with ZnO phytonanoparticles at a concentration of 75 mg/L enhanced zinc content up to 406.8% with respect to the control. The total phenols (60.5%) and flavonoids (87.8%) were also increased without having a negative effect on plant growth. The biosynthetic pathway of steviol glycosides was not affected.

The effect that the fructans of Cichorium intybus and Agave salmiana have on health, as well as on the growth of some Lactobacillus species, has been demonstrated. The aim of this work was to evaluate the effect of linear and branched fructans on the growth of seven strains and some probiotic characteristics. The molecular identification of seven strains was performed. Moreover, the growth, resistance to antibiotics and simulated gastrointestinal conditions were also evaluated when these microorganisms were grown in a culture medium containing agave and chicory fructans. The strains were identified as Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Lactiplantibacillus fabifermentans and Lactiplantibacillus paraplantarum. The results suggest that the seven Lactobacillus strains were able to grow using agave (branched) and chicory (linear) fructans. The linear and branched fructans statistically influenced the kinetic parameters. The specific growth rate varied between 0.270 and 0.573 h

Las plantas utilizan diversos mecanismos para defenderse del ataque de hongos patogenos. Algunos de estos mecanismos incluyen el aumento de metabolitos secundarios, antioxidantes, enzimas hidroliticas y polisacaridos que causan la muerte o reducen la progresion de hongos patogenos. Hemileia vastatrix (roya del cafe) es un hongo biotrofo que causa graves danos a las plantaciones de cafe. Ocasionalmente, se pueden observar plantas con ausencia de sintomas. El estudio de estas plantas asintomaticas es de suma importancia para la conservacion y mejoramiento del germoplasma resistente a H. vastatrix . Para el estudio, aquellas plantas que durante la incidencia de la enfermedad no presentaban sintomas fueron denominadas no infectadas (Ni) y las que si los presentaban como infectadas (i). Se evaluaron dos periodos: antes de la infeccion por roya y durante esta, en plantas de Coffea arabica Ni e i cultivadas en campo bajo un sistema de produccion organico. Se determino la actividad enzimatica de quitinasa, β-1-3 glucanasa y peroxidasa; ademas, de la cuantificacion de fenoles totales, acido clorogenico (3-CQA), acido criptoclorogenico (4-CQA), acido neoclorogenico (5-CQA), acido ferulico (AF), acido cafeico (AC), acido galico (AG) y cafeina (Caf). No se encontraron diferencias (p

The aim of this investigation was to determine the effect of vermicompost (V) and phosphate rock (PR) on blackberry (Rubus fruticosus L. agg.) plants inoculated with Glomus mosseae (Nicol. & Gerd.)...

The aim of this protocol was for Bonellia macrocarpa hairy root establishment and bonediol production in transformed root cultures. Cotyledons, hypocotyls and roots were used as explants for hairy root induction. Fluorescence microscopy was used for detected tandem dimer of the tomato protein (TDT). A PCR analysis for rolC was used to confirm the presence of these genes. Identification and quantification of bonediol was made for HPLC. Hypocotyls showed greater transformation efficiency (25%). Fluorescence microscopy and PCR analysis confirm genetic transformation. Bonedio production was higher in hairy roots than in complete plants.

In this paper, we present a new vector named vector total POLA (VtP), which senses arsenite as input signal, and has a signal amplifier in order to express a green fluorescent protein as a response. This vector functions in the bacterium E. coli K-12. It is demonstrated that the fluorescence signal at 530 nm of the living arsenic biosensor increases linearly with elapsed time and as arsenite concentration increases. The range has been proven to detect from 5 to 140 μg/l of arsenite. An experiment was carried out to determine the kinetic response of the bacterial biosensor as a function of arsenite concentration for 12 h, which confirmed that the development of the new vector produce a well-defined linear response as fluorescence. This measurement can be carried out in as little as 1 h at different concentrations of arsenite. A preliminary test where the bacterial biosensor was coupled with an optical fiber was performed in order to investigate the possibility of its integration as an optical fiber biosensor in the near future. The optical power output also presented a linear dependency on arsenite concentration.

Olive trees are one of the most important oil crops in the world due to the sensorial and nutritional characteristics of olive oil, such as lipid composition and antioxidant content, and the medicinal properties of its leaves. In this paper, callus formation was induced using nodal segments of olive tree (Olea europaea cv. cornicabra) as explants. Fatty acid profile, total phenolic compounds and total flavonoid compounds were determined in callus culture after 15 weeks and compared with leaf and nodal segments tissues. There was no statistical difference in phenolic compounds among leaf, nodal segments and callus culture, whereas flavonoid compounds were higher in leaf. Fatty acid profile was similar in leaf, nodal segments and callus culture and was constituted by hexadecanoic acid, octadecanoic acid, cis-9-octadecenoic acid, cis-9,12-octadecadienoic acid, cis-9,12,15-octadecatrienoic acid. Hexadecanoic acid was the main fatty acid in callus, leaf and nodal segments with 35.0, 39.0 and 40.0% (w/w), of the lipid composition, respectively. With this paper, it is being reported for the first time the capacity of callus culture to accumulate fatty acids. Our results could serve to continue studying the production of fatty acids in callus cultivation as a biotechnological tool to improve different olive cultivars.

Endosulfan lactone is a metabolite obtained from the biological oxidation of the insecticide endosulfan by action of the microorganisms present in the soil. This metabolite is more toxic and persistent than the parent compound. Therefore, it is extremely important to be able to determine the presence of this metabolite in the soil. However, accessible methods for extraction of endosulfan lactone in soil were not found in published literature. For this reason, the aim of this study was to evaluate two conventional methods of liquid–solid extraction for the determination of endosulfan lactone in solid substrate using two solvents (ethyl acetate and acetonitrile) and HPLC UV-VIS. The acetonitrile and rotary agitation extraction method was the one with the highest efficiency (97%), optimized using a factorial 32 response surface design, and validated in terms of linearity and precision. The linearity shown was r &gt, 0.999 in a wide spike level (0.15–100 mg kg−1), with the detection limit (DL) of 0.045 mg kg−1 and quantification limit (QL) of 0.15 mg kg−1. The extraction of endosulfan lactone in solid substrate using acetonitrile was more efficient than that used with ethyl acetate, so this method could be used to extract and quantify endosulfan lactone in agricultural soil.

The aim of this investigation was to determine the effect of vermicompost, vermiwash, and phosphate rock on plant, total phenols, flavonoids, and anti-oxidant activity in Piper auritum Kunth leaves. P. auritum plants were obtained from cuttings and were planted according to the Box-Behnken experimental design with three repetitions at the central point. The factors and levels were vermicompost (10, 20, and 30 g plant−1), vermiwash (5, 10, and 15 mL plant−1), and phosphate rock (1, 2, and 3 g plant−1). Plant growth parameters (plant height, stem diameter, leaves number) and chlorophyll content were measured 1 month after treatment applications. Total phenols, total flavonoids, and 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity was measured after 4 months. Vermicompost, vermiwash, and phosphate rock had no statistically significant effect on plant growth. Plant height, stem diameter, leaves number, chlorophyll, innermost number, fresh weight stem, fresh weight leaves, fresh weight root, ...

The aim of this study was analyze the effect of jasmonic acid (JA) and abscisic acid (ABA) as elicitors on fatty acids profile (FAP), phenolic compounds (PC) and antioxidant capacity (AC) in callus of Thevetia peruviana. Schenk & Hildebrandt (SH) medium, supplemented with 2 mg/L 2, 4-dichlorophenoxyacetic (2, 4-D) and 0.5 mg/L kinetin (KIN) was used for callus induction. The effect of JA (50, 75 and 100 μM) and ABA (10, 55 and 100 μM) on FAP, PC and AC were analyzed using a response surface design. A maximum of 2.8 mg/g of TPC was obtained with 100 plus 10 µM JA and ABA, respectively, whereas AC maximum (2.17 μg/mL) was obtained with 75 plus 100 µM JA and ABA, respectively. The FAP was affected for JA but not for ABA. JA increased cis-9, cis-12-octadecadienoic acid and decreased dodecanoic acid. Eight fatty acids were identified by GC-MS analysis and cis-9-octadecenoic acid (18:1) was the principal fatty acid reaching 76 % in treatment with 50 μM JA plus 55 μM ABA. In conclusion, JA may be used in T. peruviana callus culture for obtain oil with different fatty acids profile.

The aim of this investigation was to determine the effect of vermicompost and phosphate rock on plant growth, total phenols, flavonoids, flavanones, and antioxidant activity in Annona purpurea Moc & Sesse ex Dunal leaves. Annona purpurea seedlings were planted according to factorial 32 experimental design with nine repetitions. The factors were vermicompost (0, 50, and 100 g plant−1) and phosphate rock (0 and 10 g plant−1). Plant height, stem diameter, number of leaves, and chorophyll content were determined one month after application of the different treatments and total phenols, flavonols, flavanones, total flavonoids, and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity in dry leaves after 4 months. Plant height and stem diameter increased by phosphate rock, but not by vermicompost. Total phenols in leaves decreased by vermicompost. Flavonol content decreased by rock phosphate, whereas flavanones increased by vermicompost. Antioxidant activity decreased by vermicompost addition.

The aim of this study was analyze the effect of jasmonic acid (JA) and abscisic acid (ABA) as elicitors on fatty acids profile (FAP), phenolic compounds (PC) and antioxidant capacity (AC) in callus of Thevetia peruviana. SchenkHildebrandt (SH) medium, supplemented with 2 mg/L 2, 4-dichlorophenoxyacetic (2, 4-D) and 0.5 mg/L kinetin (KIN) was used for callus induction. The effect of JA (50, 75 and 100 μM) and ABA (10, 55 and 100 μM) on FAP, PC and AC were analyzed using a response surface design. A maximum of 2.8 mg/g of TPC was obtained with 100 plus 10 µM JA and ABA, respectively, whereas AC maximum (2.17 μg/mL) was obtained with 75 plus 100 µM JA and ABA, respectively. The FAP was affected for JA but not for ABA. JA increased cis-9, cis-12-octadecadienoic acid and decreased dodecanoic acid. Eight fatty acids were identified by GC-MS analysis and cis-9-octadecenoic acid (18:1) was the principal fatty acid reaching 76 % in treatment with 50 μM JA plus 55 μM ABA. In conclusion, JA may be used in T. peruviana callus culture for obtain oil with different fatty acids profile.