Recubrimientos comestibles para extender la vida de anaquel de productos hortofrutícolas

In recent years, due to post-harvest losses, the research to preserv the physicochemical, organoleptic and microbiological quality of fruit and vegetable products have gained interest. In order to offer innovative solutions for extend the shelf life on fruit and vegetable products, for its fresh consumption, the effect of edible coatings and its various components have been researched. These edible coatings, applied on the product, have the function of maintaining quality, by delaying the transport of gases (O2 y CO2) and water, by retaining volatile aroma compounds and by serving as a vehicle for antimicrobial compounds that give it the ability to inhibit the growth of microorganisms on the surface of the food; in this way its maturation process is delayed. Postharvest research trends meet consumer demand, who, nowadays, prefers to purchase fresher, "natural" food, free of synthetic additives; in addition, consumer preference is linked to a good appearance of the product at the time of purchase. The recovery of agro-industrial waste has gained interest in recent years, in order to minimize the environmental impact and take advantage of certain components to use them in the elaboration of edible coatings. The present research is a bibliographic review about some recent research of edible coatings, its various components, its effects in the conservation of fruit and vegetable products, importance and advantages of its use and opportunities for its elaboration.En los últimos años, debido a las pérdidas poscosecha, las investigaciones para conservar la calidad fisicoquímica, organoléptica y microbiológica de productos hortofrutícolas han cobrado interés. Con el fin de ofrecer soluciones innovadoras para extender la vida de anaquel de frutas y hortalizas, para su consumo en fresco, se ha investigado el efecto de recubrimientos comestibles y sus diversos componentes. Estos recubrimientos comestibles, aplicados sobre el producto, tienen la función de mantener la calidad de productos hortofrutícolas; al retardar el transporte de gases (O2 y CO2) y agua, al retener compuestos volátiles de aroma y al servir como vehículo de compuestos antimicrobianos que a su vez le confieren la capacidad de inhibir el crecimiento de microorganismos en la superficie del alimento; y de esta manera se retrasa su proceso de maduración. Las tendencias de investigación en poscosecha atienden la demanda del consumidor, quien, hoy en día, prefiere adquirir alimentos más frescos, “naturales” y libres de aditivos sintéticos; además la preferencia del consumidor está ligada a una buena apariencia del producto al momento de compra. La valorización de residuos de la agroindustria ha cobrado interés en los últimos años, con el fin de minimizar el impacto ambiental y aprovechar ciertos componentes para usarlos en la elaboración de recubrimientos comestibles. El presente trabajo es una revisión bibliográfica sobre algunas investigaciones recientes de recubrimientos comestibles, sus diversos componentes, su efecto en la conservación de productos hortofrutícolas, la importancia, ventajas de su aplicación y oportunidades para su elaboración

Sequencing of Non-model Plants for Understanding the Physiological Responses in Plants

From a genomic point of view, plants are complex organisms. Plants adapt to the environment, by developing different physiological and genetic properties, changing their genomic and expression profiles of adaptive factors, as exemplified by polyploidy studies. These characteristics along with the presence of duplicated genes/genomes make sequencing with early low-throughput DNA sequencing technologies in plants a challenging task. With the development of new technologies for molecular analysis, including transcriptome, proteome or microarray profiling, a new perspective in the genomic analysis was open, making possible to programs in species without genomic maps. The opportunity to extend molecular studies from laboratory model scale toward naturally occurring plant populations made it possible to precisely answer the longstanding important ecological and evolutionary questions. Some plant species have unique properties that could help to understand their adaptability to environment, crop production, pest protection or other biological processes. Molecular studies on non-model plants, including algae, mosses, ferns and plants with very specific characteristics are ongoing

Estudio comparativo de modelos matemáticos para predecir el poder calorífico de residuos agrícolas mexicanos

Agricultural residues represent a pollution problem because they are inadequately disposed of and high volumes of these wastes are generated. Therefore, revaluating them to produce biofuels is attractive, but, for that purpose, their calorific value should be established. Some mathematical models reported in the literature to predict calorific value have considered elemental, structural, and proximal analyses, the latter being the least expensive type. This article compares different mathematical models that have been used to predict calorific value based on elemental analysis in order to 1) evaluate agricultural residues from Mexico (bean straw, wheat straw, rice husks, and coffee husks) and other residues reported in the literature (coconut fibers and husks, garden waste, canola hulls, Jatropha curcas husks, and wheat straw) and 2) determine if the existing models work adequately for Mexican biomasses. Thus, Mexican biomasses were characterized using proximal analyses, and the calorific value of all the biomasses was estimated employing previously reported linear mathematical models. The results, which were compared with experimental values, show that the coefficients of determination of the existing mathematical models are low, particularly when Mexican biomass data are used. The best model to predict the calorific value of Mexican agricultural residues (R2 = 0.72) considers only the content of volatile matter and fixed carbon, in addition to a weak functionality of the ash content. Consequently, mathematical models should be proposed specifically for Mexican biomass.Los residuos agrícolas representan un problema de contaminación, dada su inadecuada disposición y elevados volúmenes generados. Por ello, su revalorización para producir biocombustibles es atractiva, para lo cual se requiere conocer su poder calorífico. Se han reportado modelos matemáticos para predecir el poder calorífico considerando análisis elementales, estructurales y proximales, siendo éstos últimos los de menor costo. Por ello, el presente trabajo realizó un estudio comparativo de los modelos matemáticos que predicen el poder calorífico con base en análisis elementales; dicho estudio considera: 1) residuos agrícolas procedentes de México (paja de frijol, paja de trigo, cascarilla de arroz, cascabillo de café), y 2) residuos reportados en la literatura (fibras y cáscaras de coco, residuos de jardín, cáscaras de canola, cáscaras de Jatropha curcas, paja de trigo), con el objetivo de determinar si los modelos existentes funcionan adecuadamente para las biomasas mexicanas. Para ello, las biomasas mexicanas son caracterizadas mediante análisis proximales; por otra parte, se estima el poder calorífico de todas las biomasas con modelos matemáticos lineales previamente reportados, y los resultados se comparan con los valores experimentales. Los resultados muestran que los coeficientes de determinación de los modelos matemáticos existentes son bajos, en particular al emplear datos de biomasas mexicanas. El mejor modelo para predecir el poder calorífico en residuos agrícolas mexicanos (R2 = 0.72) considera solamente el contenido de materia volátil y de carbono fijo, así como una débil funcionalidad del contenido de cenizas. Por ello, es necesario proponer modelos matemáticos específicamente para las biomasas mexicanas

Medicago sativa L. Plant Response against Possible Eustressors (Fe, Ag, Cu)-TiO2: Evaluation of Physiological Parameters, Total Phenol Content, and Flavonoid Quantification

The present study analyzed Medicago sativa L. crops irrigated by TiO2 in the anatase phase and TiO2 doped with Ag, Fe, and Cu ions at 0.1%w synthesized using the sol–gel method (SG) and the sol–gel method coupled with microwave (Mw-SG). The materials were added to the irrigation water at different concentrations (50, 100, and 500 ppm). Stress induction by nanomaterials was observed by measuring stem morphology, chlorophyll index, total phenols and flavonoids, and antioxidant activity through the DPPH (2,2-diphenyl-1-picrylhydrazy) radical inhibition assay. The nanomaterial treatments caused statistically significant reductions in parameters such as stem length, leaf size, and chlorophyll index and increases in total phenol content and DPPH inhibition percentage. However, the observed effects did not show clear evidence regarding the type of nanomaterial used, its synthesis methodology, or a concentration-dependent response. By generally grouping the results obtained to the type of dopant used and the synthesis method, the relationship between them was determined employing a two-way ANOVA. It was observed that the dopant factors, synthesis, and interaction were relevant for most treatments. Additionally, the addition of microwaves in the synthesis method resulted in the largest number of treatments with a significant increase in the total content of phenols and the % inhibition compared to the traditional sol–gel synthesis. In contrast, parameters such as stem size and chlorophyll index were affected under different treatments from both synthesis methods

Identification of Secondary Metabolites of Interest in <i>Pleurotus djamor</i> Using <i>Agave tequilana</i> Bagasse

Agro-industrial residues represent more than 60% of organic wastes worldwide, which could be used to generate other by-products or to be incorporated into other production chains. For example, bagasse is a waste from the tequila industry in Mexico that could be implemented for mushroom cultivation. Additionally, the substrate influences the growth, development, and production of secondary metabolites of fungi. This work presents a comparative experiment that studies the metabolite production in Pleurotus djamor mushrooms on agave bagasse and barley straw (traditional substrate). The biological efficiency (BE), yield, phenolics and flavonoids, antioxidant capacity, tannins, and the identification of low molecular weight metabolites were evaluated. Five treatments were proposed according to the following mixtures of agave bagasse: barley straw: T1 (1:0), T2 (3:1), T3 (1:1), T4 (1:3), and T5 (0:1). T2 had the highest yield (13.39 ± 3.23%), BE (56.7 ± 13.71%), and flavonoids (44.25 mg rutin equivalent (RE)/g); T3 obtained the highest phenol content (230.27 mg GAE/g); and T1 the highest tannins content (0.23 mg (+) catechin equivalent (CE)/g). Finally, T1 and T5 are the ones that present the greatest number of primary metabolites, including hydroxycitric acid, 2-deoxy-D-galactose, D-mannose, paromomycin, palmitic acid, pyrrole, mannitol, and DL arabinose, while in T2, T3, and T4 only two chemical compounds were found present (palmitic acid and pyrrole in T2, silicic acid and pyrrole in T3 and 2-deoxy-D-galactose and quinoline in T4). The cultivation substrate influences the concentration of bioactive molecules in the fruiting bodies of P. djamor. Additionally, P. djamor’s degradation of agave bagasse residue generates a potential application for agro-industrial residue management at a low cost

Response of Phenolic Compounds in <i>Lippia graveolens</i> Kunth Irrigated with Aquaculture Wastewater and Steiner Solution

Lippia graveolens is one of the most important aromatic species in Mexico due to antioxidant and antibiotic activities reported in its essential oil. The aim of this work was to assess the effect of irrigation with aquaculture wastewater and salicylic acid addition on the production of phenolic compounds in L. graveolens. L. graveolens plants (14) were irrigated with aquaculture wastewater and (14) using Steiner solution for 28 days; at the same time, salicylic acid was exogenously applied at 0.0 (control), 0.5 and 1.0 mM concentrations in both treatments at 5 and 19 experimental days. The total phenolic content was measured by Folin–Ciocalteu, the flavonoid content was determined by the aluminum chloride method, and the antioxidant capacity was measured by DPPH and FRAP assays. The results showed an increase in the total phenolic and flavonoid content in plants irrigated with aquaculture wastewater solution (17.25 ± 2.35 to 38.16 ± 4.47 mg eq GA·g⁻1 W). The antioxidant capacity was higher in plants irrigated with Steiner solution (98.52 mg eq T·g⁻1 W). In conclusion, L. graveolens irrigated with aquaculture wastewater leads to an increase in the total phenolic content and Steiner-solution antioxidant capacity in plants

Review and Perspectives of the Use of Alginate as a Polymer Matrix for Microorganisms Applied in Agro-Industry

Alginate is a polysaccharide with the property of forming hydrogels, which is economic production, zero toxicity, and biocompatibility. In the agro-industry, alginate is used as a super absorbent polymer, coating seeds, fruits, and vegetables and as a carrier of bacteria and fungi as plant-growth promoters and biocontrol. The latter has a high impact on agriculture since the implementation of microorganisms in a polymer matrix improves soil quality; plant nutrition, and is functional as a preventive measure for the appearance of phytopathogenic. Additionally, it minimizes losses of foods due to wrong post-harvest handling. In this review, we provide an overview of physicochemical properties of alginate, some methods for preparation and modification of capsules and coatings, to finally describe its application in agro-industry as a matrix of plant-growth-promoting microorganisms, its effectiveness in cultivation and post-harvest, and its effect on the environment, as well as the prospects for future agro-industrial applications

Effect of Salicylic Acid in the Yield of Ricinine in Ricinus communis under Greenhouse Condition

Castor bean (Ricinus communis) seeds contain ricinine, an alkaloid with insecticidal and insectistatic activities. Elicitation with salicylic acid (SA) has proven to stress R. communis and might modify the ricinine concentration. The aim of this study was to evaluate the concentration of ricinine in the bagasse of seeds from R. communis elicited with exogenous SA under greenhouse conditions. Plants were grown and divided into five groups, which were sprayed with SA and drench with 50 mL 60 days after sowing with concentrations of SA (0, 100, 300, 600 and 900 µM). Clusters were mixed and separated according to the treatment, and dried. The seeds were ground, the oil was extracted by Soxhlet with hexane, and then the bagasse was extracted with methanol. Ricinine was determined by HPLC. Elicitation did not change the plant height or diameter; the control group had 9.17 µg mL−1 of ricinine; and the concentrations followed a hormesis curve with the peak at 300 µM of SA that had a ricinine concentration of 18.25 µg mL−1. Elicitation with SA might be a cost-effective technique to increase ricinine from R. communis bagasse