The surface of peach (Prunus persica 'Calrico') is covered by a dense indumentum, which may serve various protective purposes. With the aim of relating structure to function, the chemical composition, morphology, and hydrophobicity of the peach skin was assessed as a model for a pubescent plant surface. Distinct physicochemical features were observed for trichomes versus isolated cuticles. Peach cuticles were composed of 53% cutan, 27% waxes, 23% cutin, and 1% hydroxycinnamic acid derivatives (mainly ferulic and p-coumaric acids). Trichomes were covered by a thin cuticular layer containing 15% waxes and 19% cutin and were filled by polysaccharide material (63%) containing hydroxycinnamic acid derivatives and flavonoids. The surface free energy, polarity, and work of adhesion of intact and shaved peach surfaces were calculated from contact angle measurements of water, glycerol, and diiodomethane. The removal of the trichomes from the surface increased polarity from 3.8% (intact surface) to 23.6% and decreased the total surface free energy chiefly due to a decrease on its nonpolar component. The extraction of waxes and the removal of trichomes led to higher fruit dehydration rates. However, trichomes were found to have a higher water sorption capacity as compared with isolated cuticles. The results show that the peach surface is composed of two different materials that establish a polarity gradient: the trichome network, which has a higher surface free energy and a higher dispersive component, and the cuticle underneath, which has a lower surface free energy and higher surface polarity. The significance of the data concerning water-plant surface interactions is discussed within a physiological context.

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Introduction. Currently, there are no bibliographic or statistical records that allow establishing a correlation between the physical-chemical quality characteristics of raw cow’s milk produced in the Republic of Panama and the classification it receives. Objective. To characterize and quantify the physical-chemical parameters of the quality of raw cow’s milk and correlate these characteristics with the classification that milk receives in Panama. Materials and methods. A stratified sampling was carried out according to the classification of raw cow´s milk (grade A, B, and C), 48 of grade A, 71 of grade B, and 393 of grade C. Random samples were taken in Cocle, Veraguas, Herrera and Los Santos during the rainy season from June to September 2018. In the Chiriquí province, the sampling was conducted during the dry season, from January to March 2019. In addition, it was necessary to have at least 512 producers or farms, so that the analysis reached a confidence level of 95 %, a standard deviation of 5 %, and a limit of error of 5 %. Results. The values found allow us to consider that the milk produced in Panama has the physical-chemical characteristics according to international standards. The correlation analysis indicated that the protein had a high relationship with solids non-fat (SNF), density (D), and lactose (L) (0.93, 0.91, and 0.96, respectively); also L is strongly related to SNF and D (0.94 and 0, 91, respectively). Conclusions. The analysis of variance did not allow to establish significant differences between the three existing classifications in the country, which allow a distribution of milk according to the grades of these parameters. However, it was possible to establish the existing correlation between some of these parameters.

Introducción. El envasado de alimentos ha jugado un papel importante y variado, siempre de acuerdo con los requisitos y exigencias del mercado. Actualmente, estas necesidades se centran en el objetivo de tener alimentos seguros e inocuos durante el mayor tiempo posible. Para ello, se ha ampliado el estudio y desarrollo de nuevas tecnologías para el envasado de alimentos, que proporcionan las condiciones y características necesarias para alcanzar el objetivo propuesto. Objetivo. Presentar los avances más recientes en el campo del envasado de alimentos (activo e inteligente), incluyendo las perspectivas del impacto económico alcanzado y su correspondiente proyección futura. Desarrollo. Este trabajo presenta diferentes técnicas y criterios que se consideran utilizados para proponer el concepto de envasado activo, que cuenta con las condiciones necesarias para el suministro o supresión de sustancias o componentes generados en el mismo y que contribuyen a la conservación y deterioro de los alimentos contenidos. Al mismo tiempo, se presenta la tecnología conocida como embalaje inteligente, dotada de los recursos necesarios para monitorizar, e interpretar el estado interno del envase, comunicando esta situación fuera del mismo. En ambos casos, se promueve el uso de agentes o compuestos de origen natural para minimizar sus implicaciones sobre la salud y la modificación de los alimentos implicados. Conclusiones. La generación de envases activos e inteligentes requiere una evaluación individual de cada alimento específico, frente a los componentes utilizados. Conocer las concentraciones, según la característica que se requiera controlar, y así, comprender las posibles interacciones que se pueden producir entre el contenido y el recipiente que lo contiene.

The current efforts to achieve the Sustainable Development Goals to combat and eradicate hunger have led different specialized sectors of society to launch into the search for paths that lead to it. In this sense, the research, development, and innovation (R + D + i) approach has generated various optimized methods to obtain the greatest possible benefits, through important contributions. The objective of this document is to show the advances made in the application of magnetic fields as a tool to improve the productivity of different crops. Considering the main treatment methods, characteristics of the application, and the explanation of the possible effects caused in plant entities. An attempt has been made to use scientific articles from different databases, but with important levels of reliability, measured through the impact indices involved. As a tool to know the current situation of this issue, the review of documents published, preferably, during the last decade was focused, with few exceptions, based mainly on specialized conceptualizations.

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