Determination of the Level of Ripeness and Freshness of Fruits by Electronic Sensors. A Review Determinación Del Nivel de Maduracion y Frescura de Frutos Por Medio de Sensores Elcctrónicos

Currently, there are many ways to determine the level of ripeness for fruits and vegetables, from the empirical ones, such as touching the fruit to feel its softness and even consumers smelling the fruit, to scientific ones, based on quantitative properties associated with the maturation of the fresh produce such as compression testing, gas emissions, x-rays of the interior, color of the skin or pulp, ph., and even the development of textural changes on the surface of the crop. Between these sampling techniques there are those that are invasive that lead to the destruction of the sample itself and others that use a non-destructive approach and can in some cases measure and sense ripeness over time and even in real time in determining the level of ripeness of the fruit or vegetable. A fruit is a living organism, the exchange of gases with it surrounding atmosphere is necessary to maintain its qualities. Whether the product is intact on the plant or harvested, they produce volatile organic compounds, and exchange oxygen (O) and carbon dioxide (CO2), which can be said to be the process of "breathing" of the fruit. Previous research has been developed on the assumption that fruit ripeness can be estimated by monitoring the levels of volatile organic compounds, oxygen and carbon dioxide. Others works has focused on the presence and changes in aromatic volatiles that are associated with fruit maturation. The objective of the present work is to design a programmable digital electronic platform, equipped with gas sensors and wireless networks for the development of a low-cost and rapid electronic prototype to monitor and record the levels of volatiles and exchange of oxygen and carbon-dioxide of a fruit and estimate a relationship between the gases in order to find an automated way to the determinate the level of ripeness.