Modeling a fruit using classic 3D modeling software can be a relatively complicated task. Moreover, modeling every single fruit when we need to generate a large variety of fruits of the same species is not a viable option because it is time consuming. This paper presents an original ad hoc method for modeling a wide range of 3D fruits, using a single formal grammar. Fruits are modeled by parametric 3Gmap L-systems that describe their shape and internal structure, thanks to variables and mathematical functions. At the end of our work, our method will eventually be an interesting solution to realistic modeling of fruits and their interior, and to automatic detection and recognition of real fruits.