Con el fin de contribuir a que la subjetividad en la identificación de los estados de madurez disminuya, Cenicafé desarrolló una escala de color para frutos de café, que permite reconocer ocho estados de madurez, basados en el cambio de color de los frutos, identificándolos mediante una escala numérica, que va desde 1 para los frutos inmaduros hasta 8 para los frutos secos. Este Avance Técnico presenta información acerca del desarrollo de la herramienta, la manera de usarla y cómo lograr su mejor aprovechamiento.

Smartphones show potential for controlling and monitoring variables in agriculture. Their processing capacity, instrumentation, connectivity, low cost, and accessibility allow farmers (among other users in rural areas) to operate them easily with applications adjusted to their specific needs. In this investigation, the integration of inertial sensors, a GPS, and a camera are presented for the monitoring of a coffee crop. An Android-based application was developed with two operating modes: (i) Navigation: for georeferencing trees, which can be as close as 0.5 m from each other; and (ii) Acquisition: control of video acquisition, based on the movement of the mobile device over a branch, and measurement of image quality, using clarity indexes to select the most appropriate frames for application in future processes. The integration of inertial sensors in navigation mode, shows a mean relative error of ±0.15 m, and total error ±5.15 m. In acquisition mode, the system correctly identifies the beginning and end of mobile phone movement in 99% of cases, and image quality is determined by means of a sharpness factor which measures blurriness. With the developed system, it will be possible to obtain georeferenced information about coffee trees, such as their production, nutritional state, and presence of plagues or diseases.

Con el fin de contribuir al control de la recolección en el campo, se condujo un estudio para desarrollar una herramienta práctica, exacta, económica y fácil de usar, que permitiera medir el contenido de frutos verdes durante la cosecha, de tal manera que puedan tomarse acciones correctivas que permitan tener un café de buena calidad en la tolva de recibo del beneficiadero. Este Avance Técnico muestra los resultados de la optimización de las variables masa y volumen de los frutos de café, para obtener el desarrollo del método con el recipiente Mediverdes.

The solar drying process is a critical postharvest stage for preserving coffee quality and is widely used in coffee-producing countries. A descriptive exploratory study was carried out in zones with different annual solar brightness to determine the climate variability influence on solar drying. Variables related to the evolution of drying, physical and sensory quality, and the physicochemical characteristics of the Castillo^® coffee variety were analyzed. Coffee quality was assessed by means of SCA protocol. An automatic system was designed to record variables inside the dryers and mass loss. The drying rates were different by climatic zone above and below 0.52%∙h⁻¹. Drying time was significantly longer in less solar brightness zones (Wilcoxon test). An inverse linear relationship between rewetting percentage and bean moisture was observed. Regarding coffee quality, the average scores were 81.37 and 80.93 SCA points for the climatic zones with the lowest and highest solar brightness, respectively. The bean color, water activity, acidity, and fat content did not vary between climatic zones. The coffee quality was not affected by solar drying in contrasting climatic conditions, despite the differences in drying time. Solar drying behaviors were identified that allow for the development of strategies for improving the process efficiency and management of coffee.

A partir de los resultados de las investigaciones de Cenicafé se identificaron una serie de prácticas que deben realizarse como mínimo para no alterar las características del café.

Este Avance Técnico reúne una serie de recomendaciones que se generaron a partir de la investigación, para mejorar la eficiencia del secado solar con la tecnología existente en las fincas, manteniendo como objetivo principal la conservación de la calidad del café.