Botanical-based simulation of color change in fruit ripening: Taking tomato as an example

The color change of plant fruit in ripening is a typical time-varying phenomenon involving various factors. Due to its complexity and biodiversity, it is challenging to model this phenomenon. To address this issue, we take the tomato as an example and propose a botanical-based framework considering variety, environment, phytohormone, and genes to simulate fruit color change during the ripening process. Specifically, we propose a first-order kinetic model that integrates varietal, environmental, and phytohormonal factors to represent the variation of pigment concentrations in the pericarp. Moreover, we introduce a logistic model to describe the change in pigment concentration in the epidermis. Based on the gene expression pathway of tomato color in botany, we propose a genotype-to-phenotype simulation method to represent its biodiversity. An improved method is proposed to convert pigment concentrations into color accurately. Furthermore, we propose a gradient descent-based method to assist the user in quickly setting pigment concentration parameters. Experiments verified that the proposed framework can simulate a wide range of tomato colors. Both qualitative and quantitative experiments validated the proposed method. Furthermore, our framework can be applied to more fruits.