A study I was involved in looked at consumption of fruits (and vegetables) in school children. It exposed decision-making and 'risk'. For many children - they avoid according to sensory perception.
The results show that children’s consumption of fruits and vegetables is dependent on balancing risk and reward. Children know and understand the importance of eating fruits and vegetables; however, the perceived risks are typically the prevailing determinant of consumption. These perceived risks often stem from children’s uncertainty about whether the fruits and vegetables will meet the child’s sensory preferences. To mitigate the risks perceived in eating fruits and vegetables, children employ a range of avoidance strategies. They often avoid non-ripe and over-ripe fruits. The health risk is in if they do not consume fruit over periods of time.
Article The experiences of New Zealand-based children in consuming f...
I believe it depends - consume grapes (for eg) that are unripe and you're likely to have a very upset tummy! Green bananas (eg) often get use in flour for those suffering from gluten intolerance.
You may want to explore the breakdown of fruits and the sugars within.