Fruit quality is a multi-criteria concept that is difficult to consider in modelling. It is clear that all the processes involved in the quality of fruits cannot be integrated in biological models. But some degree of complexity is needed to consider quality and the effect of environment. We are just beginning to investigate this complexity. The complexity comes from both regulations and interactions between various plant processes. This paper presents some of these regulations and interactions, and shows how the main processes can be integrated in a Virtual fruit model developed by adapting and connecting existing models describing fruit growth and respiration, sugar and acid accumulation, ethylene production and development of cuticular cracks. The Virtual fruit was used to analyze the impact of a single mutation and fruit load on fruit physiology and quality. Such a virtual approach could lead to new ways of exploring the impact of mutations, or naturally occurring genetic variations, in silico under different environmental conditions. Finally, we illustrate how the Virtual fruit could be possibly used to design fruit ideotypes for quality. Since quality is defined by several traits, we consider this design as a multi-objective optimization problem to be solved using an evolutionary algorithm.